Fixed freezing emacs when no input is provided to the meow-visit minibuffer

[bunnyanon]

When (meow-visit) is invoked and no input is provided in the minibuffer, Emacs freezes and hogs a CPU core.

this change adds a verification if text is empty, and if it is, visit-point is set to nil, triggering a visit failed message for the user.

It also adds a custom error message for this case, it being Visit <empty> failed.

[eshrh]

Thanks! This is definitely a bug.

Would you mind changing your indentation to use spaces instead of tabs? Your patch also currently touches more lines than necessary.

[bunnyanon]

Sure! indentations fixed!

[eshrh]

Originally I thought that this was probably the best way since it seems that completing-read has no built in way to disallow empty input no matter what you do; and that it's impossible to message the user about the error without using sit-for or timers.

Then I realized just now that you should probably loop until the user gives non-empty input and change the prompt itself which seems like a more user-friendly solution. Failing and stopping like in your patch is usually correct (assume the user knows what they're doing), but in this case there is literally no case where the user wants to visit empty strings -- it's invalid input and therefore shouldn't be allowed at the input stage. I went ahead and wrote this in f1bfad9. Sorry about that, but thanks again for the good catch.